Variable-speed drive



rieb. 19, 1924. 1,483,901

A; R. MCCANN VARIABLE SPEED DRIVE Feb. 19 1929:.'

A. R. MCCANN VARIABLE SPEED DRIVE Filed April 2Q'. 1921 ff i? iff;

A. R. MccANN v VRUXBLFI SPEED DRIVE -Filed April 20. 1921 y4 SheetsSheet5 1 g .if

Feb. 19, 1924.

A. R. M GCIANNA VARIABLE SPEED DRIVE 4 sheets-Shen '4 Filed April 20.1921 atraen n. MCCANN, or narrinrqn', ortie, Assieivoit, 'ifoiiiisrgit'rif' MeHriin Lrtir. l

Co., or HAMILTN, orri'o,

A ooRPoRATioN orY OHIO.

vaaraennssrnnn DRV.

applicati@ sied Apn 2o, 1921. s'er'iai N10. sensa To all whom t mayconcern: Y

Be it known that I, ALFRED R. MCCNN, a citizen ot the United States, andresident oi Hamilton, in the county of Butler and State or" Ohio, haveinvented a certain new and useful improvement in Variable-Speed Drives,of which the following is a full, clear. concise, and exact description,reference being had to the accompanying drawings, forming a part ofthis'speciiication.

illy invention relates to variable speed drives, and more particularlyto variable speed drives wherein means are Iprovided whereby theoperator can progressively increase or decrease the speed of the drivendevices without varying thel speed of the initial driving element. r l

My 'nvention finds great utility when used in connection withv a planer.In machine tools of this class, it is desirable that the machineoperations be performed in a minimum or time, and therefore a variablespeed drive must vbe provided whereby the operator can control thecutting speeds or' the various tools employed in work of this character.

The objects of my invention arer l. To provide a 'variable speed drivefor machine tools, the drive comprising a driv` ing ele-ment, a drivenelement, intermediate means connecting the elements, and'veo'ntrollingmeans for varyfing the speed of the driven element, the controllingmeans cornprising a belt, and cam actuated means for shitting the belt;n, y

2. To provideaV variable speed drive for machine tools, the drivecomprising a driving element, a. driven element, intermediate' meansconnecting the elements whereby the driven' element can be driven ineither direction, and controlling means for increasing or decreasing thespeed of the driven ele ment in one direction;

3. To provide a variable speed drive for machine tools, the drivecomprising a driving element, a driven element, intermediate meansconnecting the elements wherebyfthedriven element can be driven ineither direction, and controlling means for increasing ordecreasing thespeed of the driven element in one direction, the controlling meanscomprising cani actuated mechanism; r

4.' To provide a variable speed drive for machine tools, the drivecomprising a driving step cone pulley, a driven step cone pulley, labelt disposed around the pulleys and controllingni'eans for shifting thebelt upon the pulleys, the controlling means cornprisin'g a guideforrthe belt and cam actuated neans for displacing'l the guide;I r 5'.To provide a variable 'speeddrive vfor machine tools, the drivecomprising adrivlng step cone pulley, a, driyen 'step lcone pulley,a'pbelt disposed around the pulleys, controlling means for/shifting thebelt upon the pulleys, the controlling compris# ing a plurality ofguides `for the belt, and ca'm actuated means for successivelydisplacing the' guides. A

These and other objects of my invention will be more clearly pointed outasthezfollowing description progresses, vreference being had t0 theaoco'mpz'i'nyingv drawings, wherein-,- I i Figure l is a 'sideeleva'tionof a common type of planer, the planer being driven by means'embo'dyingthe novel features'of my invention;v f A ,y f F'fgure 2'is an endelevation of the planer; yFigl'ire is a, section taken on line of Figure1 `looking in the direction of the arrows; and I f Figures l-` and 5 are'sections' taken on line 4l-l Vand; 5 -5 respectively xof Figurev 3,looking in the direction of the arrows.`

ASin'iilar characters of reference indicate similar parts throughout theseveralviews. In Yliigures land 2,1' have illustrated' variablespeed'-drive embodyingy the novel features of my invention inc'oni'lection with' an open s ide' planer ofa'cominon typ,e.' The planercomprises a' bed 10," a platen or table 11,21' housingrl'Q' and a cross'rail 13.v Articles which are to be planed' maybe securedfupon theftable111 inthe usual manner. The tablet is adapted tol bel reciprocated uponthe bed 10, Vways 14: being provided upon the bed for this' purpose.Thehousing 12 is, provided withthe usual ways l5 whereby the'cross-rail`13 is guided when it is raised or lowered by the usual elevating screw1K6.` The tools employed inv 'the various operations areadjustably'seeured in the usual cross-rail heads 18-18'carw ried by thecross-rail 13. Thev toolsl may be brought into engagement with the workcarried upon the table l1,` and as the table .is recipro'cated, thetools when properly adjusted will' plane theJ work as desired. Duringyalternate' strokes of 'the' table-'11,f

roe

its'

t-he work will be operatively engaged by the tools, these strokes beingtermed the cutting strokes, while the intervening strokes are designatedas the return strokes. 1t is the usual practice to provide a drivingmeans which will give theJ table the highest, practical speed during thereturn strokes, the speed of the machine during the cutting strokesbeing varied to suit the particular conditions. The table 11 is drivenby a rack and pinion (not shown). rlhe rack is fastened to the table andthe pinion is operatively connected to a driven shaft which is adaptedto reverse the direction in which the pinion rotates, thereby impartinga reciprocatory motion to the table.

In the drawings, the reference character 20 designates the driven shaft.The inner end of the drivenshaft 20 is journalled in a bearing 21provided in the lower portion of the housing 12, and the outer end ofthe driven shaft is journalled in a bearing 23, formed on the lower endof a standard 24. An arm 25 of a bracket 26, rigidly secured to the topof the housing 12 and a bracket 25a, fastened to the housing 12, supportthe standard 24.

The details of the rack and pinion drive, the manner in which the shaft20 is operatively connected to the pinion, and the details of themechanism for controlling the reciprocatory motion of the table 11 arenot of importance so far as my present invention is concerned. Thereforethe foregoing brief description of these mechanisms is sufficient forthe purposes of this specification. However, some details of themechanism for controlling the reciprocatory motion of the table will bedescribed to facilitate this disclosure of my invention.

My impro-ved drive comprises the driven shaft 20, a driving shaft 28,disposed above the planer proper, intermediate mechanism, connecting thetwo shafts for driving the driven shaft 2() in either direction, andccntrolling mechanism for varying the speed of the driven shaft 20 inone direction.

A driving shaft 28 is rotatably ournaled in bearings 29 and 30, whichare secured rigidly to the bracket 26 and the standard 24 respectively.The driving shaft 28 may be connected operatively with any suitablesource of power, but in the preferred form of my inventionA` I employ amotor, as at 31, which is connected directly to the inner end of thedriving shaft 28 by the shaft coupling 32.

The intermediate mechanism connecting the driven shaft 20 and thedriving shaft 28 comprises a plurality of pulleys disposed upon the twoshafts, and a plurality of belts adapted to co-operate with the pulleys.Referring to Figure 3, it will be noted that a pulley 34 and a step conepulley 35 are rigidly secured to the driving shaft 28, the cone pulley35 being disposed towards the outer end of the shaft. Interposed betweenthe pulleys 34 and 35, and rotatably journaled upon the shaft 28, is apulley 36. The driven shaft 2O has a pulley 38 fixed thereon and a stepcone pulley 39 and a vpulley 40 rotatably journaled upon it. The pulley40 is interposed between the pulleys 38 and 39. Another pulley 41 isinterposed between the pulley 38 and the bearing 21, and is rotatablyjournaled upon the shaft 20.

As shown in Figures 2 and 3, the cone pulley 35 is turned to fourdifferent diameters. The cone pulley 39 has five belt engaging surfaces,four of which are aligned with the four diameters of the cone pulley 35.An endless belt 43 is disposed around the cone pulleys 35 and 39. Thebelt 43 is adapted to operatively engage any pair of aligned diametersof the two pulleys, and to be shifted from one pair to another. As thecone pulley 35 is rigidly secured to 'the driving shaft 28, the speed ofthe cone pulley 39 may be increased or decreased by shifting the belt43.

The additional surface turned upon the cone pulley 39, as indicated at45, is operatively connected by an endless belt 46 to the pulley 36,disposed upon the driving shaft 28. The pulley 36 co-operates in turnwith the loose pulley 40, disposed adjacent the diameter 45 of the conepulley 39 by means of a twisted belt 47. The twisted belt 47 will ofcourse cause the pulley 40 to revolve in a direction opposite to that inwhich the pulley 36 revolves, Disposed around the pulleys 34 and 41 isan endless belt 48.

The tight pulley 38 is turned to two diameters as indicated at 50 and51. rl`he diameter 50 is equal to the diameter of the loose pulley 41,and the diameter 51 is equal to the diameter of the loose pulley 40. Itis apparent that the belt 47 may be shifted to operatively engagediameter 51, and that the belt 48 may be shifted to operatively engagethe diameter 50, the pulleys 34 and 36 being provided with faces ofsufficient width to permit such displacements of the belts.

.When the belt 48 is shifted to the diameter 50 of the pulley 38, thedriving shaft 28 may rotate the driven shaft 20, which actuates theaforementioned rack land pinion whereby the table 11 is driven. rl`hedirection in which the table is driven by the belt 48 is termed thereturn stroke, the cutting stroke being made by means of the belt 47when it is shifted to the diameter 51 of the pulley 38. The belts 47 and48 are `automatically and alternately shifted to engage the pulley 38 bymeans comprisingv a plurality of shifting levers 47a and 48 adapted toguide the belts 47 and 48 respectively. rEhe shifting levers areoperatively connected to the usual mechanism carried upon the bed 10 andhousing 12 of the planer is indicated ico y,

y ll. During the operation of the planer, the

lll)

39 is rotated trips and resetting devices 11a-1P willV cause themechanism l0a to alternately shift the belts 47 and 48 into engagementwiththe tight pulley 38, thereby giving the table ll its reciprocatorymotion. In the usual construction of planers of this type, 'provision ismade whereby the operator may disengage the levers 47a' and 48a from theactuating mechanism l03L when the levers arein the neutral position asshown. Thus the table ll may be brought to rest without firstdisconnecting the driving shaft 28 from its source of power, or in thisinstance, without stopping the motor 3l. n

I will now describe the manner in which the speed of the belt 47 isvaried'.

As hereinbefore described, the cone ul-` ley 35, rigidly secured to thedriving shaft 28, will rotate the cone pulley 39 by means of the belt43, the speed at which the pulley depending upon what pair of aligneddiameters ofthe two pulleys the belt is contacting.v The pulley 39 willdrive bythe belt 46, and the the loose pulley 36 pulley 36 will drivethe pulley 38 when the belt 47 is shifted to engage that pulley. As' thebelt 47 is twisted' ina. welll known manner, the pulley 38 is driven ina direction op* posite to that in which' it is driven by the belt 48. i

The controlling means for varying the speed of the driven shaft 20during the cutting strokes comprises cam actuated means for shifting thebelt 43 upon the cone' pulleys 35 and 39. The beltis guided by a pair ofbelt loops 43ar and 43".

The loopy 43a is disposed `around the belt 43 adjacent the point whereit runs onto the pulley 35, the loop 43b being similarly disposed nearthe pulley 39. The belt 43 travels in the direction indicated by thearrows 53-53 (Figures l and 2).

To shift a belt disposed around a pair of cone pulleys, that portion ofthe belt which is to be shifted to a smaller diameter of one of thepulleys must be displaced before that portion to be shifted to a largerdiameter of the other pulley can be made to slip onto the largerdiameter. The reason for this is apparent.

The belt loops 43a and 43b are adapted to so shift the belt 43. Each ofthe loops 43":l and 43b is secured upon the free end of one of a pair ofrods 54 and 55, the loop 43a being secured to the rod 54, and the loop43b to the rod 55. The rods 54 and 55 are carried by slides 56 and 57respectively, the slides being slidably journalled upon a plurality ofrods 58, disposed in a bracket 59 which is secured to the standard 24.As shown in Figures 4 and 5, each of the slides 5e amir 57" .has an'f'airi-fricuony feuer e0 adapted to ride in the cam track 61 of a camk62. TheV cam 62 is rigidly secured to a shaft 63 rotatably journalledin thel bracket 59, the shaft 63 projecting throughr the standard 24 to'receive a handle 64. The handle 64 is provided with a spring actuatedlatch 65, which is yieldingly urged towards lthe standard l24 andadapted to enter a depression in thepouter end of a set screw 66,threaded into'lthe standard 24. The latchy 65.is provided with a headportion 67 whereby it may be withdrawn from the depression in the setscrew 66.l The handle 64 and latch are of well kn-owr'iv construction,-andv it is readily understood'that the cam 62 may be rotated eitherdirection by means ofthe handle, and locked against rotationy 'by meansof the latch, after it completes each 360 of angular displacement.`

Referring to Figure 5, ity will' be noted thatthe cam track 6l consistsof a slot in the cylindrical surface of the cam. The cam tracklcomprises a plurality yof dwells 69v and leads 70, eachdwel-l beingadapted to hold one of the anti-friction rollers y60 substantiallystationary whilev the cam Vis rotated through 180o."v The dwells 69 -areequally spaced apart distances equal to the widths of the faces of thefour aligned diameters of the cone pulleys 35 and 39.` The leads 70'connect adjacent dwells so thatl bj continuously rotating the cam in`one ldirection, an anti-friction roller 60 could be made to traverse thetrack from one end `of the cam to` the other. friction rbllers 60-60are' diametricall-y positioned relatively to the cam, it is apparentthat when the cam Ais being rotated, the rollers will alternatelyadvance and rest. Thisy structure permits the belt to be displaced to asmaller diameter of one of the cone pulleys before it is shifted to thelarger diameter of the other cone pulley. Therefore if the belt 43 is tobe shifted to occupy the largest diameter of the cone pulley 35, ythehandle 64 is rotated in a counter-clockwise direction (Figure l), thusdisplacing the belt loop 43b so that 'the belt 43 will shift to the nextsmaller diameter of the cone pulley 39. The belt loop 43a will thenshift the belt 43 to the largest diameter of the cone pulley 35, the camhaving been rotated through 360.

Tn the operation of thegplaner, the belts 47 and 48 are automaticallyand alternately shifted as hereinbefore described, to operatively engagethe pulley 38. This results in reciprocatory motion of the table 1l. Tovary the speed at which the belt 47 drives the pulleys 38 during thecutting strokes, the operato-r need only rotate the cam 62 in a properdirection until the belt 43 is disposed around two aligned diameters ofthe cone pulleys 35 and 39, which are propor- However, as vthel antillitioned to impart the desired speed to the pulley 36, which in turndrives the belt L17.

While I have thus described the details of one form of my invention, itis to be understood that I am not;limited to these details except by thescope of the appended claims.

What I claim is: y V 1. In mechanism ofthe class described, thecombination of a drivingy shaft, a driven shaft, two drivingpulleysrespectively fixed and loose on the driving shaft, two drivenpulleys of different diameters fixed on the driven shaft, a beltengaging the fixed driving pulley and adapted to be shifted onto thedriven pulley of smaller diameter, a belt engaging the loose drivingpulley and adapted to be shifted onto the driven pulley of largerdiameter, one of the belts being open and thev other belt crossed,reversely stepped pulleys respectively fixed on y the driving shaft andloose on the driven shaft, a belt engaging the stepped pulley on thedriven shaft and the loose driving pulley, a belt engaging the twostepped pulleys, and means for' shifting the last-named b-elt. 2. Inmechanism of the class described, the combination of driving shaft, adriven shaft, two driving pulleys respectively fixed and loose on thedriving shaft, two driven pulleys of different diameters fixed on the`driven shaft, a belt engaging the fixed driving pulley and adapted to beshifted ontothe driven pulley of smaller diameter, a belt engaging theloose driving pulley and adapted to be shifted onto thedriven pulley oflarger diameter, one of the belts being open and the other belt crossed,reversely stepped pulleys respectively fixed on the driving shaft andloose on the driven shaft,

a belt engaging the stepped pulley onthe driven shaft and the loosedrivingpulley, a belt engaging the two stepped pulleys,

belt-Shifters `respectively engaging the last'-A named belt adjacent theSteppe pulleys, and manually operable means tokmove' the beltshifterssuccessively. f i

3. In mechanism of the class described, the combination of a drivingshaft, a driven shaft, two driving pulleys respectively lfixed and looseon the driving shaft,l two driven pulleys of different diameters fixedon the driven shaft, a belt engaging the fixed driving pulley andadapted to be shifted onto,

the driven pulley of smallerA diameter, a belt engaging the loosedriving pulley and adapted to be shifted-onto the driven pulley oflarger diameter, one of the belts being open and thev other beltcrossed, reversely stepped pulleys respectively fixed on the drivingshaft and loose on the driven. shaft, a belt I engaging the steppedpulley on the driven shaft and the loose driving pulley, a belt engagingthe two stepped pulleys, belt-shifters respectively engaging thelast-named belt adjacent the stepped pulleys, a manually rotatable camhaving a groove alternately circumferential and helical, and memberssecured to the belt-Shifters andmengaging in the groove, one of themembers en gaging a circumferential portion of the groove while theother member is engaging a helical portion thereof.

In witness whereof, I hereunto subscribe my name this first day ofApril, 1921.

ALFRED R. MG'oANN.

Witnesses ALBERT CLUTZWIG, HARRY I-I. SCHUSTER.

